In recent years, capacity of semiconductor devices is advancing to 255 MDRAM and 1 GDRAM. With the advance in capacity of semiconductor devices, package technologies adopt C4 (controlled collapse chip connection) rather than SOC (system on chip). Hence, WaferLevel package technologies are widely used to package semiconductor devices.
Such WaferLevel package technologies require development of vertical-type electric contactor of a probe card for testing ball-shaped pads arranged in a matrix.
As illustrated in FIG. 1(a), conventional vertical-type electric contactor includes a body 2 having a square-column shape and a plurality of protrusive tips 1 formed on the bottom of the body 2. Each of the tips 1 has a pyramid shape or a truncated pyramid shape, and the tips 1 and the body 2 is a single body. The body 2 and the tips 1 are each made of conductive material such as nickel or nickel alloy. As illustrated in FIG. 1(b), a cylindrical body 3 may be provided.
FIG. 2 shows the example where such a conventional vertical-type electric contactor is used. Generally, a vertical-type electric contactor is vertically fixed to a probe card by a predetermined physical force, contacting a test portion of a to-be-tested substance such as a ball-shaped pad 4 of a semiconductor device. Thereafter, an electrical signal is applied to the pad 4 to test whether the semiconductor device is normal.
In the event that the semiconductor device is tested by means of the conventional vertical-type electric contactor, the body 2 or 3 is inelastic or fragile. A sufficient overdrive (OID) value may not be obtained with the shape of the body 2 or 3. Moreover, it is difficult to efficiently distribute a reaction force generated at a probe tip 1 when the probe tip 1 contacts the pad 4 to secure a sufficient OID value that a probe card needs.